Cleaning solvent and dispenser

ABSTRACT

A liquid cleaning solvent is formulated from a terpene hydrocarbon present in a concentration of about 50 percent to about 90 percent of the cleaning solvent and tetrahydrofuran compatible with the terpene hydrocarbon present in a concentration of about 10 percent to about 50 percent of the cleaning solvent. The liquid cleaning solvent is provided in a dispensing pen for ease of application.

BACKGROUND OF THE INVENTION

The present invention is directed to a cleaning solvent. Moreparticularly, the present invention is directed to a readily applyablecleaning solvent and a dispenser, in pen form, for use in applying thesolvent.

A wide variety of solvents are available for commercial, as well asnon-commercial uses. Many of these known solvent cleaners are quiteaggressive and thus cannot be used on many plastic or other polymericmaterials. It has been found that these materials can tend to degradethe plastic thus resulting in structural failure of the plastic,aesthetic and like failures. Other types of cleaning solvents areineffective and, as such, provide little to no efficacy.

It has also been found that many of the known solvents do not have awide usage range period. That is, while one particular type of solventmay be quite useful to, for example, remove gum or labels (e.g.,glue-removal), this same solvent may not be useful to, for exampleremove and industrial coatings. On the other hand, a solvent that isuseful in removing industrial coatings may be too aggressive for use inglue removal.

It has also been found that many such cleaning solvents are notavailable in a readily usable container. That is, such solvents may bespray applied or brush applied or merely provided in a container, suchas a metal can. Those who have used such solvents will recognize thatspray applicators may not be useful in certain situations to, forexample, remove small areas of glue. On the other hand, brushapplicators may not be useful where a very specific or discrete locationrequires application of the solvent.

One known solvent is available in a pen-type dispenser. The solvent isformulated from d-limonene and is commercially available from Micro CareCorporation of Bristol, Conn. under the trademark Tidy Pen®.

Accordingly, there exists a need for a cleaning solvent that can be usedin a wide variety of applications from glue removal to coating removal.More desirably, such a solvent is provided in a readily usabledispenser.

BRIEF SUMMARY OF THE INVENTION

A liquid cleaning solvent is formulated from a terpene hydrocarbonpresent in a concentration of about 50 percent to about 90 percent ofthe cleaning solvent and tetrahydrofuran compatible with the terpenehydrocarbon present in a concentration of about 10 percent to about 50percent of the cleaning solvent.

A preferred terpene hydrocarbon is d-limonene. Preferably, the liquidcleaning solvent includes butylated hydroxy toluene present in aconcentration of less than about 1 percent of the cleaning solvent. Mostpreferably, the butylated hydroxy toluene is present in a concentrationof less than about 0.1 percent of the cleaning solvent

A preferred solvent is provided within a dispenser. A preferreddispenser is a pen dispenser.

These and other features and advantages of the present invention will beapparent from the following detailed description, in conjunction withthe appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become morereadily apparent to those of ordinary skill in the relevant art afterreviewing the following detailed description and accompanying drawings,wherein:

FIG. 1 is an exploded view of an exemplary pen for use with the liquidcleaning solvent embodying the principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred embodiment with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentillustrated. It should be further understood that the title of thissection of this specification, namely, “Detailed Description Of TheInvention”, relates to a requirement of the United States Patent Office,and does not imply, nor should be inferred to limit the subject matterdisclosed herein.

In the present disclosure, the words “a” or “an” are to be taken toinclude both the singular and the plural. Conversely, any reference toplural items shall, where appropriate, include the singular.

A present liquid cleaning solvent includes a terpene hydrocarbon presentin a concentration of about 50 percent to about 90 percent of thecleaning solvent and a tetrahydrofuran (“THF”) compatible with theterpene hydrocarbon. The tetrahydorfuran is present in a concentrationof about 10 percent to about 50 percent of the cleaning solvent. In apresent solvent, the THF is inhibited with butylated hydroxy toluene ina concentration of less that about 0.1 percent of the THF.

In a present cleaning solvent, the terpene hydrocarbon is a D-limonene.Referring now to the figures and in particular to FIG. 1 there is showna cleaning device 10 having liquid cleaning solvent embodying theprinciples of the present invention. The cleaning device 10 illustratedis a pen dispenser, which will be discussed in more detail below.

A liquid cleaning solvent in accordance with the present invention hasbeen found to be useful for a wide range of applications. For example,it has been found that present liquid cleaning solvent is useful inapplications as straight forward as glue removal to, for example, removethe glue that may remain after a label has been removed from an object.It has also been found that the present liquid cleaning solvent can beused in applications which require more aggressive solventcharacteristics. For example, it has been found that the present solventworks well to remove conformal coatings. Those skilled in the art willrecognize that conformal coatings are those coatings that are applied tocircuit boards to provide protection for the circuit board assembly(including the solid state devices thereon) from environmental exposure.

It will also be recognized that in order to perform any necessarymaintenance on the circuit board, e.g. to remove and replace components,these conformal coatings must be fully removed from the area of intereston the circuit board. Conformal coatings include various types ofprotectants. Typically, conformal coatings are acrylic based, urethanebased or silicone-based compounds. It has been found that the acrylicbased compounds provide good dielectric protection, the urethane basedcoatings exhibit good overall toughness and typically cannot be removed,while the silicone based coatings provide good protection fromenvironmental elements.

It has been found that the present liquid cleaning solvent exhibits good“removal” characteristics for each of these types of conformal coatings.

Those skilled in the art will recognize that the THF is a stronglyaggressive solvent, and has a correspondingly strong odor associatedwith it. As such, it is often necessary to use THF in non-confined orventilated areas. In addition, this strong odor discourages use of thissolvent in other than commercial applications.

On the other hand, it will also be recognized that the terpenehydrocarbons generally have less aggressive solvent characteristics, aswell as less offensive odors. In that many such terpenes are formed fromessential oils or resins and balsams, these oils are often found to berather “fragrant”. That is, these oils can have fragrances ranging fromconifer like to citrus like. As such, these solvents are more attractivefor use in a non-commercial setting. However, one drawback to thesesolvents is there that their solvent characteristics, e.g., strength,are less than optimal.

To this end, it has been found that a certain mixture of a terpenehydrocarbon and THF provide the requisite aggressiveness desired incommercial as well as non-commercial solvents, while maintaining a morepleasing fragrance (or less offensive odor). It has been found that acleaning solvent having a terpene concentration of about 50 percent toabout 90 percent of the cleaning solvent and THF in a concentration ofabout 10 percent to about 50 percent of the cleaning solvent providesthe requisite aggressiveness of a solvent, while maintaining a pleasingfragrance. In a preferred cleaning solvent, the terpene, preferablyd-limonene, is present in concentration of about 90 percent of thecleaning solvent and the THF is present in a concentration of about 10percent of the cleaning solvent. In a most preferred cleaning solvent,the THF is inhibited with butylated hydroxy toluene in a concentrationof less that about 1 percent, and most preferably, in a concentration ofless than about 0.1 percent of the THF.

Various plastics were evaluated to determine whether a cleaning solventembodying the principals of the present invention, when applied to theplastics resulted in unacceptable levels of degradation of the plastic.In these evaluations, samples of each plastic measuring one-inch by(varying widths and thickness) were immersed in the liquid cleaningsolvent for a period of 15 minutes. The samples were then allowed to dryand final measurements were taken. Rankings were then assigned to eachof the samples based upon the PDL resistance rating chart. Table 1 belowsummarizes the results of these evaluations.

The samples evaluated include: acrylonitrile butadiene styrene (ABS),Buna-N, ethylene propylene diene monomer (EPDM), graphite, Lexan®,neoprene, Noryl®, polypropylene, polyvinyl chloride (PVC), siliconerubber, Teflon® and Viton®.

TABLE 1 CLEANING SOLVENT/PLASTICS COMPATIBILITY Initial Final Wt.Initial Final Thickness Initial Final Width Plastic Type Wt. Wt. ChangeThickness Thickness Change Width Width Change Ranking ABS 0.6524 0.67043% 0.0655 0.0675 3% 0.5065 0.5085 0%  5-Good Buna-N 0.8104 0.9531 18%0.067 0.073 8% 0.4995 0.5335 7%  1-Poor EPDM 1.4516 1.6867 16% 0.1260.1345 7% 0.508 0.5245 3%  1-Poor Graphite 1.9045 1.9045 0% 0.129 0.1290% 0.5115 0.5115 0% 10-Excellent Lexan 2.065 2.07 0% 0.216 0.216 0%0.5035 0.5035 0% 10-Excellent Neoprene 1.3316 1.5278 15% 0.1195 0.13110% 0.4945 0.5205 5%  1-Poor Noryl 1.009 1.1262 12% 0.12 0.1245 4% 0.5140.514 0%  5-Good Polypropylene 0.4766 0.477 0% 0.0045 0.0645 0% 0.50150.5045 0% 10-Excellent PVC 0.7153 0.7158 0% 0.063 0.063 0% 0.504 0.5040% 10-Excellent Silicone 0.7021 0.9721 38% 0.0655 0.077 18% 0.5045 0.57614%  1-Poor Rubber Teflon 2.3291 2.3294 0% 0.1285 0.1285 0% 0.49550.4955 0% 10-Excellent Viton 1.8256 1.8283 0% 0.1215 0.1215 0% 0.49250.494 0% 10-Excellent

In TABLE 1 above, the first column represents the type of plasticevaluated. In certain instances, commercial or trade names (trademarks)are shown, rather than generic chemical nomenclature/names for ease ofrecognition. The second, third and fourth columns illustrate datarepresenting the initial and final weights and weight change, in percent(%), before and after immersion in the present liquid cleaning solvent.The data in columns five, six and seven represent the initial and finalsample thicknesses and the change in thickness, and the data in columnseight, nine and ten represent the initial and final widths and change inwidth, again, before and after immersion. The eleventh column is aranking based upon the compatibility or acceptability of the sample, inwhich the sample were assigned a ranking of 1 (poor compatibility oracceptability), 5 (good compatibility or acceptability) or 10 (excellentcompatibility or acceptability).

As can be seen from the data of TABLE 1, there is a wide variety ofplastics that exhibit excellent or good compatibility with the presentcleaning solvent. Notably, only Buna-N, EPDM, neoprene and siliconerubber exhibited unacceptable rankings (rankings of 1), whereas all ofthe other plastics evaluated exhibited acceptable compatibility with thepresent cleaning solvent. Also notably, graphite, Lexan®, polypropylene,PVC, Teflon® and Viton® all exhibited exceptional characteristics, vis,essentially zero percent (0%) change in weight, thickness and width ofthe samples.

Returning again to FIG. 1, a dispensing pen 10 for use with the presentliquid cleaning solvent S is of a known design. The pen 10 includes abody 12 defining a sealed chamber 14 in which the cleaning solvent S isstored. A nib 16 is formed from a porous material, such as polyester,and is mounted to the body 12 by a biased valve assembly 18. The nib 16has a marking end 20 and a supply end 22 from which the solvent S issupplied to the marking end 20. A typical pen 10 includes a cap 24 toprevent the pen 10 from drying out. Such a marking pen 10 iscommercially available from ITW Mark-Tex of Roseland, N.J.

The nib 16 is biased to an outward position in which it extendsoutwardly from the body 12 and valve assembly 18. The supply end 22 ofthe nib 16 is positioned in the valve assembly 18. When a (downward)pressure is applied to the nib 16, the nib 16 urges the valve assembly18 open which permits the solvent S to flow from the chamber 14, intothe valve 18 and into contact with the nib supply end 22. This saturatesthe nib 16 with the solvent S which flows through the nib 16 to themarking end 20. Contact of the marking end 20 with an item, thus resultsin applying the solvent S to that particular desired area of the item.

Those skilled in the art will, however, appreciate that the presentmarking cleaning solvent can be used in a variety of applications. Forexample, the solvent can be used in the above-noted pen dispenser.Alternately, the solvent can be provided in bulk form and can be appliedby spray, brush or aerosol application. Alternately still, the solventcan be applied by dipping a desired part in the liquid solvent solution.

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

What is claimed is:
 1. A liquid cleaning solvent comprising: a terpenehydrocarbon present in a concentration of about 50 percent to about 90percent of the cleaning solvent; tetrahydrofuran compatible with theterpene hydrocarbon present in a concentration of about 10 percent toabout 50 percent of the cleaning solvent; and butylated hydroxy toluene.2. The liquid cleaning solvent in accordance with claim 1 wherein theterpene hydrocarbon is d-limonene.
 3. The liquid cleaning solvent inaccordance with claim 1 wherein the butylated hydroxy toluene is presentin a concentration of less than about 1 percent of the tetrahydrofuran.4. The liquid cleaning solvent in accordance with claim 3 wherein thebutylated hydroxy toluene is present in a concentration of less thanabout 0.1 percent of the tetrahydrofuran.
 5. The liquid cleaning solventin accordance with claim 1 wherein the solvent is contained within adispenser.
 6. The liquid cleaning solvent in accordance with claim 3wherein the dispenser is a pen dispenser.
 7. A liquid cleaning solventcomprising: d-limonene concentration of about 90 percent of the cleaningsolvent; and tetrahydrofuran compatible with the terpene hydrocarbonpresent in a concentration of about 10 percent the cleaning solvent. 8.The liquid cleaning solvent in accordance with claim 7 includingbutylated hydroxy toluene present in a concentration of less than about1 percent of the tetrahydrofuran.
 9. The liquid cleaning solvent inaccordance with claim 8 wherein the butylated hydroxy toluene is presentin a concentration of less than about 0.1 percent of thetetrahydrofuran.